﻿<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title></title>
</head>
<body>
    <form>
        <label><input type="checkbox" name="noread" />未读</label>
        <label><input type="checkbox" />未读</label>
        <label><input type="checkbox" />未读</label>
        <label><input type="checkbox" />未读</label>
        <label><input type="checkbox" id="all" />全选</label>
    </form>
    <script>
        //参考消息页面：完成勾选全选功能
        document.getElementById('all').onclick = function () {
            var all = document.getElementsByTagName('input');
            for (var i = 0; i < all.length - 1; i++) {
                all[i].checked = this.checked
            }
        }
        function negation(parameter) {
            return !parameter
        }
       
    </script>
</body>
</html>